Method of manufacturing elastic fabrics



1948. T. G. HAWLEY, JR., ET AL 2,434,111 I @METHOD OF MANUFACTURINGELASTIC FABRICS Filed Feb. 24, 1944 2 Sheets-Sheet 1 BYQVE 2 ATTORNEYJan. 6, 1948. T. G. HAWLEY, JR., ET AL 2,434,111

' METHOD OF MANUFACTURING ELASTIC FABRICS Filed Feb. 24, 1944 2 Sheets-Sheet 2 ATTORNEY Patented Jan. 6, 1948 METHOD OF MANUFACTURING ELASTICFABRICS Thomas G. Hawley, Jr., St. Paul, Minn., and Nicolai Timenes,Waterbury, Conn., assignors to United States Rubber Company, New York,N. Y., a corporation of New Jersey Application February 24, 1944, SerialNo. 523,756

9 Claims.

This invention relates to an improved method of making an elasticfabric, by adhesively combining elastic material with an extensiblelayer of textile fabric, and particularly to such method wherein theelongation of the textile fabric in the finished product is increaseduniformly throughout in one direction, as compared to its normal state,by gathering the opposite edges of the textile fabric, and stretchingsame in a direction transversely to such edges prior to combining theelastic material with the textile fabric.

It is known that textile fabric such as a knitted fabric when stretchedtransversely in the direction of its courses, and a fabric such as abiascut woven fabric when stretched transversely and diagonally of thethreads, will contract in the loncedure the knitted fabric Was stretchedtransversely in the direction of the courses, so as to contract thefabric in the direction of the wales, and while so stretched the layerof fabric was combined with an elastic layer of rubber by adhering therubber thereto.

The above process is described in United States Patent No. 2,004,110,gran-ted June 11, 1935, to P. H. Head. In that process provision was notmade to permit the knitted fabric to contract freely and uniformly as itwas being stretched transversely which is necessary in order to obtainthe maximum elongation and uniformity of stretch in the finished elasticfabric. Although it is stated in the above mentioned patent that thetreatment of the fabricmay be continuous there is no disclosure as tohow the textile fabric may be continuously stretched transversely andthe elastic material continuous but successively and simultaneouslyapplied thereto. The problem of permitting the textile fabric tocontract freely particularly arises when the fabric is processedcontinuously, as when it is stretched transversely on a tenteringmachine where the opposite edges of the fabric are held in afixedposition along the diverging inelastic chains of the machine so 2that it is restrained from contracting longitudinally when it isstretched transversely.

The process constituting the present invention is adapted to be carriedout continuously and permits the textile fabric to contract freely anduniformly in one direction when it is stretched in the direction atright angle to the direction of contraction. The term textile fabric isused here in the sense that the fabric is capable of so stretching andcontracting. The direction of the contraction of the fabric is referredto as the longitudinal direction and the direction at right anglesthereto is referred to as the transverse direction. It is also to beunderstood that the term contraction means the longitudinal shorteningof the fabric resulting from stretching it transversely. In accordancewith the practice of the present invention, a transversely stretchabletextile fabric is first gathered along its opposite longitudinal edgesin an amount substantially equal to the desired longitudinal contractionof the fabric, which should be at least 15% of the normal finishedlength of such edges. The fabric is then stretched transverselybetweenthe edges, and although such edges may be held in a fixed position bythe tenter frame, the fabric is free to contract longitudinally as itmoves along the diverging sides of the tenter and is being stretchedtransversely. While the textile fabric is held in the transverselystretched condition, an elastic layer of material, such as for example,natural or synthetic rubber, or rubber composition or rubberlikematerial, or other elastic plastic, is adhered to and elasticallycombined with the fabric. The elastic material may be applied to thetextile fabric in accordance with procedures heretofore used, such as byapplying a coating of rubber or other plastic containing fluid to thefabric and thereafter drying and/or vulcanizing the solids depositedfrom. the fluid to form an elastic layer adhered to the fabric, or theelastic material may be calendered on the fabric, and in the case of avulcanizable material, it may be subsequently vulcanized.

The operation of gathering the longitudinal edges of the textile fabricprior to stretching it in the transverse direction is an improvementover the prior process because by so doing the textile fabric ispermitted to freely contract in the longitudinal direction and thefabric is thereby imparted greater extendibility and more uniformelongation throughout than was heretofore obtained, and the finishedcomposite elastic fabric is provided with the same improved qualities.The gathering operationalso makes it possible to perform the process ina continuous manner on a tentering machine and thereby producerelatively long lengths of the elastic fabric without any seams.

The method practised in this invention will be described more fully inconnection with the accompanying drawings, in which Fig. 1 is a planview of an apparatus which is suitable for performing the methodpracticed in this invention;

Fig. 2 is a plan view of a fragment of a transversely extendible textilefabric showing one of its longitudinal edges, which has beenigathered ona sewing machine and stitched to hold the gathering in place;

Fig. 3 is a plan view of an apparatus capable of carrying out anotherform of the method;

Fig. 4 is a cross-section of a portion of the apparatus shown in Fig. 3,and illustrating the mechanism for gathering one of the longitudinaledges of the textile fabric; and

Fig. 5 is an end view of the apparatus shown in Fig. l'ta'ken on a line5-45 of Figs. 3 and 4.

In the practice of the ;present invention by the use of the apparatuslfl, shown in Fig. l, the longitudinal edges H of the transverselystretchable textile fabric 12 are first uniformly gathered on a sewingmachine, Or by any other suitable means, so -as to gather the edges asillustrated in Fig. 2. However, as shown in the latter figure only oneof the edges -ll is shown as gathered by the stitches 13, it beinunderstood that both edges are to be gathered similarly. The gatheredfabric may be wound on a roll [4, or may be draped in a box, and is ledfrom the roll or box to the transverse stretching apparatus It, which isa tenter frame of a common type. The opposite edges H of the fabric areled into the left end of the machine, as viewed in Fig. l, and aresecured to pins 115 carried by the chains "5 and 1 1 of the tenter frameT0.

The top reach of chains travel from the left to the right as indicatedin Fig. l by the arrow A, and they diverge from another in suchdirection. As the fabric travels from the left end of the machinetowards the right endfit is stretched laterally due to divergence of thechains, and that much of the original capacity of the fabric to stretchtransversely is subtracted and added to the capacity to stretchlongitudinally, thereby potentially increasing the longitudinalelongation of the fabric. Since the edges 'H of the fabric 12 are in agathered state on the chains, they can contract without being restrainedby the fixed position of the edges on the chains iii and H. Thedivergent course of the chains 55 and IT turns .at the hinged points 19to about-a parallel course. During the travel of the fabric along suchcourse, the elastic material "is combined with the stretched textilefabric.

As shown in Fig. 1, the elastic rubber containing fluid '20, from whichthe elastic material -to be combined with the fabric is derived, isapplied by a doctor blade 2i to form a coating 22 which is set andconverted into an elastic medium by a drier 23. The coating may also beVulcanized 'while passing through the drier23, if desired. As the coatedand dried composite elastic fabric 2 reaches the end of the tenter frameF8, it may be removed therefrom and wound on a roll 25. If desired thecoating may be dried to a tacky condition and another layer of fabricmay be adhered to the tacky coating which maybe subsequently vulcanized.I

The tenter frame chains '16 or ll are support- 3'4 which is driven by apulley keyed to the shaft 32, and drives a pulley 36 keyed to a shaft 3?on which is aflixed the roll 25.

The distance between the parallel sides of the tenter frame 1 0 isadjustable and the diverging sides are pivoted at [9, and 38 for thepurpose of controlling the transverse stretch of the fabric l2, and alsofor the purpose of accommodating different widths of the textile fabricl2 in its normal condition as it enters the feed end of the frame at theleft. Circular brushes 39 containing relatively stiff bristles aremounted on the feed end of the "tenter frame over the tenter pins 15 forthe purpose of pressing the edges of the fabric 12 on the pins 15 as.the fabric is led between the brushes and the pins. The brushes 39 aremounted on the shafts All which are rotatably mounted in brackets llwhich carry the sprockets 2'6 and '2"! for the tenter chains l6 and "IT.The supporting structure for the brushes 39 is more particularly shownin Fig. 5 of the modification of the apparatus for carryin out the otherform of the method practiced in this invention.

The other form of this method is carried out by the apparatus shown inFigs. '3 to 5 of the drawings. The method described in connection withthese figures is similar to the method described in connection withFigs. 1 and '2, excepting that the longitudinal edges of the fabric arenot stitch-gathered prior to applying the edges to the tenter pins, buton the other "hand the edges are gatheredand applied "In .a gatheredcondition to the "pins without the stitches.

As illustrated in Fig. 4 of the drawings, the

textile fabric 42 in its normal finished condition is led from a roll 43whichis positioned over the tenter frame 44. As shown in Figs. '3, '4,and 5, the longitudinal edges '45 of the "fabric 42 are led into thegathering devices '36 positioned on each side of the feed 'end of thetenter frame 44. The gathering device on each -side'comprises two'intermeshing gears 4-7 and 48 which are shown in detail in Figs. '4 and'5. The edges of the fabric pass between the "gears 41 and '48 and, asshown in Fig. '5, the margin 39 of the fabric extends outside of thegears and is positioned directly over the tenter pins 50. A slackness orgathering is imparted to the edges G5 by the gear teeth 5-1 and 52 ofthe respective gears 4'! and 48. As the extending marginal edges '49 arepressed into contact with the traveling tenter pins 5'0 on the ten ter:chains .53 by the gear M, the bristle brushes 54 positioned directlyover the pins 50 press the :edges t!) *on to the pins so as to firmlysecure the gathered edges thereto. As will be noted in :Fig. 4, :as thefabric passes from the :brushes 54, the marginal edges'49 are providedwith gathers .or folds between th pins 50.

The tenter chains 53 are constructed and driven in the manner describedwith reference to Figs. 1 and 2. As the fabric4'2 is carried in thedirection of the arrow 'B by the divergent course of the chains 53, itis stretched laterally between its edges i5, which are secured to thepins '50. After the fabric reaches the parallel course 51 of the towhich the tenter pins 50 are affixed.

Brackets 62 are secured to each of the channels 58 of the tenter frameat the feed end for the purpose of supporting the ends of the channelsand the tenter chain sprocket 63. The sprocket 63 is mounted on a shaft64 which carries a sprocket 65 and drives a chain 65 which, in turn,drives a sprocket 61 which is keyed to a shaft 68. The shaft 68 ismounted in the bracket 62 and the gathering device gear 48 is mounted onthe shaft 68 and drives the gathering mechanism.

The gathering device gear 41 is mounted on a stub shaft 69 which isrotatably mounted in an overhanging arm of the bracket 62. The bristlebrushes 54 are mounted on stub shafts H which rotate idly in an arm 12of the bracket 62.

While the preferred forms of this method have been described herein, itwill be understood that changes in the details as described may be madewithout departing from the spirit of the invention and the scope of theappended claims.

Having thus described our invention, what we claim and desire to protectby Letters Patent is:

1. The method of making elastic fabrics comprising the successive stepsof uniformly gathering up the opposite edges of a textile fabric,uniformly stretching said fabric transversely to and between said edgesby gradual increments until the fabric has been contracted in thedirection of the gathered edges, and rendering said fabric elastic byadhesively combining elastic rubber containing material with saidtextile fabric while said fabric is so stretched.

2. The method of making elastic fabrics comprising the successive stepsof uniformly gathering up at least 15% of the normal length of theopposite edges of a textile fabric in relatively small gathers,uniformly stretching said fabric transversely to and between said edgesby gradual increments until the fabric has been contracted in alengthwise direction in an amount substantially equal to the amount saidedges were gathered up, and rendering said fabric elastic by adhesivelyuniting an elastic layer of rubber containing material to said textilefabric with an elastic bond while said fabric is so stretched.

3. The method of making elastic fabrics comprising the successive stepsof uniformly gathering up at least 15% of the normal length of both ofthe longitudinal edges of a textile fabric, uniformly stretching saidtextile fabric transversely to said edges by gradual increments untilthe said textile fabric has been contracted in the direction of saidedges in an amount substantially equal to the percentage of thegathering, applying an adhesive rubber containing liquid to saidtransversely stretched fabric, and converting said liquid into anelastic medium while said fabric is so stretched.

4. The method of making elastic fabrics comprising the successive stepsof uniformly gathering up at least 15% of the normal length of both ofthe longitudinal edges of a textile fabric which is adapted to contractin the direction of said edges when stretched transversely thereto,uniformlystretching saidtextile fabric transversely .age of thegathering of the longitudinal edges, :applying an adhesive rubbercontaining liquid to said transversely stretched fabric, and drying saidliquid sufficiently to convert it into a coherent elastic layer whilesaid fabric is so stretched.

5. The method of making elastic fabrics comprising the successive stepsof uniformly gathering the longitudinal edges of a transverselystretchable and, longitudinally contractable textile fabric until thegathered lengths of saidedges are less than of their normal length,uniformly stretching said textile fabric transversely by gradualincrements until the textile fabric has been contracted in a lengthwisedirection sufficiently to smooth out the gathering in the centralportion of the textile fabric, coating the textile fabric with anadhesive rubber containing liquid while it is transversely stretched,and converting the liquid into an elastic medium.

6. The method of making elastic fabrics comprising the successive stepsof uniformly gathering the longitudinal edges of a transverselystretchable and longitudinally contractable textile fabric until thegathered lengths of said edges are less than 85% of their normal length,uniformly stretching said textile fabric transversely by gradualincrements until the textile fabric has been contracted in a lengthwisedirection sufficiently to smooth out the gathering in the ce tralportion of the textile fabric, coating the textile fabric with anadhesive rubber containing liquid'while it is transversely stretched,and drying said liquid and vulcanizing the rubber so as to convert theliquid into an elastic medium.

7. The method of making elastic fabrics comprising the successive stepsof introducing an initial longitudinal slack in a transverselystretchable textile fabric, by uniformly gathering the longitudinaledges of said fabric so that the athered length is less than 85% of itsnormal length, stitching said edges to retain them in said gatheredcondition, uniformly stretching said textile fabric transversely bygradual increments until the textile fabric has been contracted in thelengthwise direction in an amount substantially equal to the amount saidedges were gathered, and rendering said fabric elastic by adhesivelyuniting an elastic layer of rubber containing material to saidtransversely stretched textile fabric with an elastic bond.

8. The method of making elastic fabrics comprising the successive stepsof uniformly gathering up at least 15% of the normal length of both ofthe longitudinal edges of a textile fabric which is adapted to contractin the direction of said edges when stretched transversely thereto,uniformly stretching said textile fabric transversely by gradualincrements until the said textile fabric has been contracted in thedirection of said edges in an amount substantially equal to thepercentage of the gathering of the longitudinal edges, applying to thetransversely stretched fabric a rubber containing liquid, and dryingsaid liquid to convert the residue into an elastic layer adhesivelyunited to said textile fabric whil it is so stretched.

9. The method of making elastic fabrics comprising the successive stepsof uniformly gathering up the longitudinal edges of a textile fabric,and thereafter continuously moving said fabric REFERENCES CITED The"folluwing references are of record in fi-he file of this patent:

Ntrmber Nmriber UNITED STATES Name 'Da'te I Head June '11, 1 935 fiawleyJune 13.11939 Teague 'Feb.25, 1 941 FOREIGN PATENTS Country Date Germany001;.2'6, 193-8

